Incandescent lamp.



- No. 669,306. Patented Mar. 5, IN".

J. w. HOWELL.

INCANDESGENT LAMP.

(Applies-tied filed Nov. 25, 1898.)

(No Iodol.)

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tty- UNITED STATES ATENT i-Trice.

JOHN IV. IIOIVELL, OF NEWARK, NEW JERSEY, ASSIGNOR TO THE GENERAL ELECTRIC COMPANY, OF NEW YORK.

INCANDESCENT LAMP.

SPECIFICATION forming part of Letters Patent No. 669,306, dated March 5, 1901. Application filed November 25. 1898. Serial No. 697,335. No model-) To all whom it may concern: between these the lamp is slipped. The ter-, Be it known that 1, JOHN IV. HOWELL, a minals, therefore, of my invention extend citizen of the United States, residing at Newalong each side of the lamp and furnish an ark, in the county of Essex, State of New Jerefficient support forthe fragileglass structure, 55 soy, have invented certain newand usefulImso that the breakage is negligible.

movement-sin Incandescent Lamps, (Case No. In another form of iny invention I may use 885,) of which the following is a specification. the terminals in the way just pointed out My present invention relates to the conthat is, connected to the filament by lead-in struction of incandescent lamps of the type wires sealed through the end of the lamp, 6o now commonlyknownin theartastelephonebut extending along its sides and forming a I lamps, especially designed for use in telesupport for the glass structure without havphone-switchboards, taking the place of other ing any base attached to them. In this case and morecomplicated forms of annunciators. it is preferable to insulate the ends of the ter-' The construction of these lamps has been peminals, so that if they be accidentally brought 65 I5 culiarly difficult. They are extremely minute, in contact there will be no short circuit formed. being only about a quarter of an inch in diam- Inasmuch as the voltage at which these lamps etei'. The old type, which my inventionis deare operated is so low, only a moderate insusigned to replace, was constructed of a small lation is needed for this purpose; piece of glass tube having fitted to its sides The accompanying drawings show several 70 a pair of copper terminals and provided with different forms of lamp which embody my platinum lead-in wires for the filament, passinvention. ing through the side of the lamp. 'As these In the drawings, Figures 1 and 2 are a perlamps were designed to be used with small spective and side elevation, respectively, of current and at low voltage and were provided a lamp made according to my invention. Figs. 75 with very attenuated filaments, the support 3, 4, and 5 are aperspective of a lamp, a side of which was of platinum, and since a very elevation of one of the terminals and the base, high degree of skill was required in the conand a section upon the line 3 3 of Fig. 4 of struction, they were unduly expensive, costanother form of lamp. Fig. 6 is a perspecing several times as much as standard lamps tive of a different form, Figs. 7 and 8 being, 80 0 of sixteen-candle power. As ordinarily conrespectively, sections on the line 7 7 of Fig. structed in the way just pointed out these 8 and line 8 8 of Fig. 7 of the form of lamp lamps had ,no base, but were simply short shown in Fig. 6, the bulb being omitted. pieces of glass tube having exterior termi- A is the lamp in Figs. 1 and 2, of which nals. They were peculiarly liable to break- B B are the terminals. Lead-in wires d cl, 0f 85 age, and, since the seal between the platinum platinum, are secured to the opposite termiand the glass was so short, in a little time the nals B B by solder, as shown at a. A wrapcontraction and expansion breaks the seal ping e, of fabric, covers the terminals and, andimpairs the vacuum. It is to obviate the as shown at the ends, completely envelops difficulties attendant upon this style of lamp them, so that should the ends be pressed to- 0 that I have devised my present invention. gether they would still be insulated suffi- In my improved lamp in one form I provide ciently for lamps of this type. A coating of a base, to which the terminals are attached, insulating-varnish, such as shellac, is usually and use afilament of the ordinary arched form, applied over the fabric, which should be thin having lead-in wires of platinum sealed and light.' I have used ordinary adhesive 5 5 through the end of the lamp with a considercourt-plaster for this purpose with good sucable thickness of glass by methods commonly cess. Of course this construction might be in use. With such an extremely small lamp applied to either of the other forms of lamp it is inconvenient to use any of the common shown in the drawings; but in those provided forms of base or socket. The ordinary telewitha base it will ordinarily be unnecessary. I00

phone-switchboard has simplya pair of clips, In Figs. 3, i, and 5, A is the lamp, B B forming opposite terminals of a circuit, and being the terminals. These are lightened by slots 6 cut through them, the slots serving to make the terminals more flexible, so that they maybe pressed. into place readily. This has the furt-herobject of providing a flat place with which the terminals may register to hold the lamp in proper position,which in the other forms of lamp shown, as in Figs. 1 and 6, is effected by cutting a slot in the brass of the terminal Without removing any part of the latter. 0 is the base, which in this case is formed of wood,though otherinsulation might be used. The terminals B B are crimped into the slots 0 in the base,and a punch-mark 6' holds them against longitudinal displacement.

The form of lamp shown in Figs. 6, 7, and 8 also embodies the invention, though differing somewhat in construction from the others. In it the terminals are shown at B B D representing the usual high-resistance filament in all of the lamps. The terminals are embedded in the base 0 as shown in Figs. '7 and 8, the latter being formed of any suit able insulation, which may be molded. Glass may be used for this purpose or any other desired substance.

An essential feature of novelty in the invention is the support of the bulb or vacuum-chamber by the terminals, which extend along its sides and which are connected to the filament by lead-in wires, sealed in through the ends of the lamp. This construction may be embodied in a lamp with or withouta base, as is manifest from the exa mples here shown; but any form of lamp employing it I consider Within my invention.

While my invention is intended principally for use in telephone systems, it may be employed in all cases where a very small lamp is required, as for medical or dental purposes, where it is required to explore the recesses of the body.

What I claim as new, and desire to secure by Letters Patent of the United States, is

1. An incandescent lamp having terminals upon the sides of the bulb, andlead-in wires sealed in through the end of the lamp.

2. In an incandescent lamp, the combination of a glass chamber inclosing a filament of high resistance, with lead-in wires of platinum sealed through the end of the lamp, and terminals extending along the sides of the bulb and supporting the lamp.

3. In an incandescent lamp, the combination of a tubular inelosure for the filament, terminals extendingalong the sides of the inclosure and secured to the base, and lead-in wires passing through the ends of the lamp and connected to the terminals.

4. A miniature incandescent lamp of tubular form, having lead-in wires sealed into the ends and permanently connected to curved terminals of sheet metal embracing the sides of the tube, and means carried by the tube for clamping the sheet-metal terminals into close engagement with the wall of the tube.

5. A miniature incandescent lamp having lead-in wires through the base, a glass seal of greater length than the thickness of the bulb, and terminals permanently secured to the lead-in wires embracing the sides of the bulb.

6. A miniature incandescent lamp having an arched filament, lead-in wires sealed into the base through a glass seal of greater length than the thickness of the bulb, and two terminals mounted on the sides of the bulb.

7. In a telephone-lamp, the combination of an inclosed chamber for the filament, terminals extending along the sides of the chamber and held in place by a piece of compressed molded insulating material surrounding a portion of them, and lead-in wires sealed through the end of the lamp and connected to the terminals.

8. In a telephone-lamp, the combination of a tubular vacuum-chamber inclosing the filament, terminals on the sides of the lamp, lead-in Wires passing through the end of the lamp and connected to the terminals, and a wrapping of fabric holding the terminals in place.

In witness whereofI have hereunto set my hand this 18th day of November, 1898.

JOHN W. HOXVELL.

Witnesses:

S. N. WHITEHEAD, JOHN E. MITCHELL, Jr. 

